This paper seeks to identify the factors driving air transport services, with special emphasis on the role played by tourism-related variables. Using data on flows of passengers arriving to airports in the Spanish Mediterranean region, we employ panel data regressions for the period 2004-2015. Explanatory factors in the model include variables reflecting the state of development of the tourism market, the size of the local economic activity, and the presence of low-cost carriers. Cointegration techniques are applied in order to control for the presence of unit roots in variables of the model. Main results show the relevance of tourism activities in explaining air transport passenger services in this area.